1. Field of the Invention
The present invention relates to a surgical instrument for grasping a needle and performing tissue anastomosis and so forth under the observation by endoscope.
2. Description of the Related Art
A type of bypass surgery has been known during which coronary artery revascularization of the heart for example is performed using an endoscope, wherein an endoscope, a surgical instrument to be used as a needle-holding device, and forceps and so forth are inserted into the chest cavity via a trocar which punctures the chest wall, an anastomosis opening is created by cutting open a portion of the coronary artery with scissors, the internal thoracic artery is brought to the anastomosis opening with the grasping forceps, and the internal thoracic artery is anastomosed to the anastomosis opening and connected thereto with the surgical instruments.
With such a surgery, U.S. Pat. No. 5,951,575 for example describes a known configuration wherein an insertion unit having a curved portion on the tip portion is provided, and a pair of jaws which can turn about the axis of the insertion unit and which can open and close at the tip portion of the insertion unit are provided, as a surgical instrument which anastomoses tissue particularly by grasping a suture needle. A driving cable for transmitting turning force and opening/closing force to the tip of the insertion unit is passed from the operating unit through the insertion unit to the tip.
Also, USP 2002/156497 discloses a surgical device with a configuration having forceps with a large degree of freedom, which transmits turning force and opening/closing force of the treatment unit with three links.